Cotton harvester harvesting rotor speed monitor frequency indicator

ABSTRACT

The present invention provides a method and system for monitoring the rotor speed of the harvesting rotors of a cotton harvester. The inventive rotor speed monitor determines the rotational speed of each individual rotor. The individual speeds of the rotors are combined and an average rotor speed computed. The individual rotor speed is then compared with the average speed for the combined rotors. An alarm is provided to alert the operator whenever the rotational speed of a given rotor differs by a predetermined amount from the average rotational speed for the combined rotors. The invention rotor speed monitor can provide an early indication of rotor malfunction and also detours false signals generated by the harvester rotors deceleration after completion of the harvesting operation on a cotton row.

FIELD OF THE INVENTION

The field of the present invention is of cotton harvesters. Moreparticularly the field of the present invention is for rotational speedmonitors for the picker spindle rotors of a picker type cotton harvesterand the stripper brush rolls of a stripper type row cotton harvester.

DISCLOSURE STATEMENT

Row cotton harvesting machines are of two basic types. One basic type ofcotton harvester is a cotton stripper. Cotton strippers harvest thecotton by removing the total boll from the plant. Pivotally andforwardly mounted from the frame of the cotton stripper is a pluralityof harvesting units or drums. Within each drum of the cotton stripper,there are two adjacent generally parallel mounted brush rolls whichrotatably strike the cotton plant to remove the boll from the cottonplant. The boll is then transported by an auger screw and pneumaticconveyor system to a receptacle mounted on top of the vehicle frame.

Picker type cotton harvesters have a harvesting drum with two verticallymounted picker spindle rotors transversely separated by a fore-and-aftplant passage. Each picker spindle rotor has a plurality of picker barswith operative picker spindles. The picker spindles interact with thecotton plant to remove the cotton lint from the cotton boll. Each pickerspindle rotor is provided with a doffer for removing the lint from thepicker spindles. The lint is then transported by a pneumatic conveyor toa receptacle mounted on top of the frame of the cotton harvester.

In both picker and stripper type cotton harvesters deviation fromstandard operating rotational speed of the harvesting rotors is often anindication of harvesting unit malfunction or overload. In stripper typeharvesters a retardation of the brush row rotational speed indicates afailure in the drive system, or a choked condition. In picker typecotton harvesters the rotor speed will be retarded when there is anoverload. Also, picker type cotton harvester's rotor speed will becomeuncharacteristically high when a drive chain has failed.

McBee U.S. Pat. No. 4,282,702 provides a monitor for detecting anoverload condition on the picker drum of a cotton harvesting unit. McBeeprovides a leaf spring contact supported above a slip clutch having adriven portion meshing with a driving pinion. An overload conditionforces the driven portion upward against the contact, shorting thecontact to a unit frame which causes the overload indicator lamp on theoperator's panel to light.

McBee can only be used on harvester rotors utilizing a slip clutch.McBee can monitor an overload condition but is not suitable for use fordetection of overspeed conditions. McBee is most suitable for conditionswhere the malfunction causes a torque overload of the harvesting rotor.

Hubbard et al. U.S. Pat. No. 4,306,403 provides an overload sensor for acotton harvester unit drive. Normal tension in the belt drive to theharvesting unit input shaft is balanced by an adjustable spring load.Overload of the input shaft overcomes the spring load to activate anelectrical switch that alerts the operator by lighting a warning lamp.The input drive includes a slip clutch, and the spring load is adjustedso that a warning is provided before the drive load reaches the loadingwhich would cause the clutch to begin to slip. Hubbard et al. like McBeesenses overload conditions. It is not suitable to monitor harvestingrotor malfunctions which do not manifest themselves by increases in thetorque requirement of the rotor.

Prior to the present invention it had been known to monitor theindividual speed of a rotor. However, prior monitoring systems whichmonitor individual rotor speed only have a tendency to issue falsealarms when the rotor slows down after completion of the harvestingoperation on a plant row.

SUMMARY OF THE INVENTION

To overcome the disadvantages of prior overload sensors for cottonharvester harvesting unit rotors and drives, and prior rotational rotorspeed monitors, the present invention is brought forth. The presentinvention provides a rotational speed monitoring system and method whichindividually monitors the separate speeds of a plurality of harvestingrotors. The rotational speeds of the total rotors is combined and thenan average is computed. The individual harvesting rotor speed of eachrotor is then compared with the average rotational speed of the combinedrotors. If a rotor's rotational speed differs from the averagerotational speed of the combined rotor by a predetermined differential,an alarm signal is activated.

It is a desire of the present invention to provide a cotton harvesterharvesting rotor speed monitoring system. It is also a desire of thepresent invention to provide a cotton harvester harvesting rotor speedmonitoring system which lowers the possibility of false alarms caused bythe rotors slowing down after finishing the harvesting operation at theend of a plant row.

Other desires and advantages of the present invention will becomeapparent to those skilled in the art as the nature of the invention isbetter understood from the accompanying drawings and detail description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of the picker type cotton harvester;

FIG. 2 is a perspective view of a stripper type cotton harvester;

FIG. 3 is a top elevational view illustrating the drum on a four-rowpicker type cotton harvester; and

FIG. 4 is a schematic view of the cotton harvester harvesting rotorrotational speed monitoring system.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIGS. 1 and 3, a picker type cotton harvester 10 typicallyhas a wheeled frame 12 with a receptacle, commonly referred to as abasket 14 mounted on top. Pivotally extending forwardly from the wheeledframe are the harvesting units, or drums 16, 18, 20 and 22. A series ofpneumatic conveyors 24 transport the harvested lint cotton from thedrums to the basket inlet 16.

Representative drum 16 has a pair of picker spindle rotors 28 and 26transversely separated by a fore-and-aft plant passage 30. Pickerspindle rotors 28 and 26 have corresponding doffers 32 and 34 forremoving the cotton from the picker spindles. The harvested cotton isthen transported by the pneumatic conveyors 24 to the basket inlet 16.

To ensure that the drums are functioning properly, the rotational speedsof the spindle rotors are monitored. An overload condition on a givenspindle rotor will usually manifest itself by a decrease in speed ofthat rotor. A failure in the drive chain of the drive system whichpowers the rotors will usually manifest itself in a rotor reachingexcessive speeds.

The stripper cotton harvester 80 of FIG. 2 has substantial similaritieswith the picker type cotton harvester. However, the stripper cottonharvester 80 functions to remove the boll from the cotton plant insteadof harvesting the lint from the boll as the picker cotton harvesterdoes. Each of the harvesting units 82, 84, 86, and 88 of the strippertype cotton harvester has two parallel mounted rotating brush rollers 90and 92. The brush rollers have alternating lengths of nylon bristles andrubber flaps. The nylon bristles and rubber flaps of the two rollerscooperate with one another to strip the cotton boll from the plant. Thespeed of rotation of the brush rolls is also monitored to indicate tothe operator of the various malfunctions which may occur in theharvesting units.

Referring to FIGS. 3 and 4, harvesting rotors 26, 28, 36, 38, 40, 42,44, 46 have individual speed monitors. The output from each individualspeed monitor is fed into the averaging processor 50. The averagingprocessor calculates the average rotational speed for all of the rotors.The average speed is fed to a comparison processor 52. The comparisonprocessor compares the average rotational speed with the individualspeed of each rotor. If the rotor speed of any individual rotor differsby a predetermined amount from the average speed, the alarm 54 isactivated.

The differential speed which activates the alarm will be set by designcriterion and typically can be in a range of plus 10% or minus 20%.Also, when a rotor speed slows to the alarm point and the alarm istriggered, that rotor speed is dropped from the averaging calculation sothe average is not unduly distorted by the slow rotor.

By comparing the rotational speed of each individual rotor with theaverage rotational speed of the combined rotors, false alarms areeliminated when ending the harvesting operation.

The alarm mechanism may be further modified such that, the alarmmechanism is deactivated when the average rotational speed for thecombined rotors is lower than a predetermined amount. By deactivatingthe alarm at low speed levels, false alarms are eliminated wheninitially activating the harvesting unit or disengaging operation of theharvesting unit.

Another modification for the alarm system is to use the frequency of thealarm system to inform the operator of which rotor is malfunctioning.The frequency change can be utilized with either audio or visual alarmsignals. Typically, on a four-row harvesting machine four alarm lights(one for each harvesting unit) will be mounted within the cab. Todifferentiate between the front and rear rotors the flash rate of thesignal light will be used. A high frequency (fast) flash rate may beused to indicate a malfunction in the front rotor. A low frequency(slow) flash may be used to indicate a malfunction in the rear rotor. Ifdesired, one light may be used for both rotors and an audible signalwith a short pause may indicate the front rotor and an audible signalwith long pauses may indicate the rear rotor.

While a few embodiments of the present invention have been explained, itwill be readily apparent to those skilled in the art of the variousmodifications which can be made to the present invention withoutdeparting from the spirit and scope of this application as encompassedby the following claims.

What is claimed is:
 1. A cotton harvester with a plurality of harvestingrotors having a rotor speed monitoring system comprising:rotorrevolutional speed counting means; averaging means to determine theaverage rotational speed of the combined rotors; alarm means activatedby a predetermined differential rotational speed of a rotor from theaverage rotational speed of said combined rotors; and frequency signalmeans to indicate which rotor has a rotational speed which differs fromthe average rotation speed of the combined rotors by predeterminedamount.
 2. A cotton harvester as described in claim 1, wherein saidfrequency signal is audible.
 3. A cotton harvester as described in claim1 wherein said frequency signal is visual.